Windows 10, FireFace 800...

Interesting issue.... I've had this Fireface for maybe 6-8 years, and just this year, input 10 started making a constant, but low volume static noise.... It sounds just like the end of a vinyl record where the needle endlessly plays the paper label, and also similar to the hiss from a blank cassette tape. It's loud enough where, even with the input trim on the front of the FF800 trimmed to the lowest level, you can hear it at normal listening levels if everything is silent. The sound appears in recordings too, so it's not just heard in monitoring. The sound is there whether something is plugged into input 10 or not. Input 9 of the same monitoring "channel" has no issues, so to silence the noise I either can't use channel 9/10, or just pan it left to channel 9. The sound increases in volume slightly if I enable 48v on input 10.

I have tried reinstalling the drivers several times and updating the firmware. I have the most recent updates for both, on a Windows 10 machine.

Any ideas? Thx much folks!

EDIT: can someone please move this to the vintage forum... i didn't realize the FF800 was vintage